do you have to break on switch staements c code example

Example 1: switch statement in c

#include <stdio.h>

int main(void)
{
  	int a = 0;
  
    switch(a)
    {
       case 1 :
          statement("a = 1");
          break;

       case 2 :
          printf("a = 2");
          break;

       default :
       	  printf("a is neither 1 or 2");
	      break;
    }
}

Example 2: switch case c

switch(expression) {

   case constant-expression  :
      statement(s);
      break; /* optional */
	
   case constant-expression  :
      statement(s);
      break; /* optional */
  
   /* you can have any number of case statements */
   default : /* Optional */
   statement(s);
}